Experimental results are presented of the piloted ignition delay time and the upward flame-spread rate over the surfaces of insulated electrical cables under an externally applied radiant flux. The objective of the experiments was to assess and rank the fire performance of seven types of complex cables commonly used in electrical installations. The experiments were carried out with 46 em long single cables that were suspended vertically and exposed to irradiance levels ranging from 0.5 -2.5 W/cm 2 • Some of the cables had a conducting core, and some did not. A simplified analysis, similar to that developed by Quintiere and coworkers was developed to indentify the parameters that dominate the fire characteristics of the cable. A method similar to that proposed by the above authors was applied to develop flammability diagrams and to define the flame spread properties of the cable materials in an attempt to assess and rank the fire performance of the seven types of cable. It is shown that the method can be successfully applied and that it provides a simple way to rank the cables and to calculate the parameters important to ignition and flame spread in electrical cables. The study also explores the feasibility of predicting the piloted ignition performance of the cable insulations using thermogravimetric analysis (TGA) data in conjunction with the ignition and flame spread formulas by proposing that the surface temperature at which thermal degradation produces pryolyzate is related to the ignition temperature for that particular material. The predicted ignition delay times are compared with experimental results and it is shown that for most polymers, the temperature at which thermal degradation is first Observed can be used to estimate ignition delay times, particularly at high irradiance levels.

We summarize our research in FY 82 for the DOE-sponsored project, Fire Protection Research for DOE Facilities. This research program was initiated in 1977 to advance fireprotection strategies for energy technology facilities to keep abreast of the unique fire problems that develop along with energy technology research. Since 1977, the program has broadened its original scope, as reflected in previous year-end reports. We are develop ing an analytical methodology through detailed study of fusion energy experiments at Lawrence Livermore National Laboratory (LLNL). Using these experiments as models for methodology development, we are concurrently advancing three major task areas: (1) the identification of fire hazards unique to current fusion energy facilities; (2) the evaluation of accepted fire-management measures to meet and negate hazards; and (3) the perfor mance of unique research into problem areas we have identified to provide input into analytical fire-growth and damage-assessment models. ' HRR = Heat-release rate. b VCAB-4 averaged 15 kW c ring experiment. ' Test was terminated before it reached i|uast-ec|u:'librium. ''This fire did MO I fill the pan. 'The polystyrene fire changed the heat transfer of the walls. We can note the difference In the temperatures o(the lest runs alter (lie I he |>olvMvreiie. ' This fire should have been a 200 kW fire but it was a 100 kVV (lie for Hie firsl two minutes. " A leak in the sample diluted all of these measurements. 11 MOD 7 ran 800 seconds longer Hun MOD 1.

Prepared for US-DOE Assistant Secretary for Environment, Safety and Emergency Preparedness; Office of Operational Safety, Washington, DC 20545r--.T. '. r ''*"• I;;JKS1 IS UNIIMIUI msci.-miER I hK document »as prepared as an account of «ork sponsored !»\ an agenct of the I nited Stales < internment. Neither I fit-I niled Slates t.oternmenl nor the I niu-rsit> of ( alifomia nor any of their emjlotecs. makes anv warrant*, express or implied, or assumes anv legal liability or responsibility for the accurao. com pleteness, or usefulness of anv information, apparatus, product, or process disclosed, or represents that its use »oufd not infringe pri>atel> owned rights. Reference herein to anv specific commercial products, process. or senice b\ trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or impK its endorsement, recommendation, or famring h> the I niled States (internment or the I niversitv of* alifornia. I he ijews and opinions of authors expressed herein do not nccessarilv stale or reflect these of the t niled Man-, (.oiernmeni thereof, and *hall mil he used for adu-rtisiug or product endorsemenl purposes.Work performed under the auspices of the t .S. Department of rnerg* h> I a w mice I i I ahurat»r> under ( onlract \\ -74f)5-Fng-4H.

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